U.S. patent number 8,521,447 [Application Number 13/529,738] was granted by the patent office on 2013-08-27 for method, system, and computer software code for verification of validity of a pressure transducer.
This patent grant is currently assigned to General Electric Company. The grantee listed for this patent is John William Brand, Eugene A. Smith, David Carroll Teeter. Invention is credited to John William Brand, Eugene A. Smith, David Carroll Teeter.
United States Patent |
8,521,447 |
Smith , et al. |
August 27, 2013 |
**Please see images for:
( Certificate of Correction ) ** |
Method, system, and computer software code for verification of
validity of a pressure transducer
Abstract
A method that includes comparing a first brake pressure measured
at a first transducer that is part of a braking system on a lead
powered unit of a distributed power (DP) system to a second brake
pressure measured at a second transducer that is part of a braking
system on a remote powered unit of the DP system. The method also
includes determining whether the second transducer is functioning
within designated operational parameters when the DP system is
operating in a DP mode based on comparing the first brake pressure
to the second brake pressure.
Inventors: |
Smith; Eugene A. (Satellite
Beach, FL), Teeter; David Carroll (Melbourne, FL), Brand;
John William (Melbourne, FL) |
Applicant: |
Name |
City |
State |
Country |
Type |
Smith; Eugene A.
Teeter; David Carroll
Brand; John William |
Satellite Beach
Melbourne
Melbourne |
FL
FL
FL |
US
US
US |
|
|
Assignee: |
General Electric Company
(Schenectady, NY)
|
Family
ID: |
43382975 |
Appl.
No.: |
13/529,738 |
Filed: |
June 21, 2012 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20120260716 A1 |
Oct 18, 2012 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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12504028 |
Jul 16, 2009 |
8224591 |
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Current U.S.
Class: |
702/41 |
Current CPC
Class: |
B60T
17/22 (20130101); B60T 13/662 (20130101) |
Current International
Class: |
G01L
25/00 (20060101) |
Field of
Search: |
;702/41 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lau; Tung S
Attorney, Agent or Firm: GE Global Patent Operations Kramer;
John A.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser.
No. 12/504,028, which was filed on Jul. 16, 2009 (the "`028
Application"). The entire subject matter of the `028 Application is
incorporated by reference.
Claims
What is claimed is:
1. A method comprising: comparing a first brake pressure measured
at a first transducer that is part of a braking system on a lead
powered unit of a distributed power (DP) system to a second brake
pressure measured at a second transducer that is part of a braking
system on a remote powered unit of the DP system; and determining,
using one or more processors, whether the second transducer is
functioning within designated operational parameters when the DP
system is operating in a DP mode based on comparing the first brake
pressure to the second brake pressure, wherein determining, using
the one or more processors, whether the second transducer is
functioning within the designated operational parameters includes
determining that the second brake pressure is invalid; wherein each
of the lead and remote powered units is a separate and distinct
powered unit capable of providing tractive efforts to the DP
system, the lead and remote powered units being directly or
indirectly coupled to each other.
2. The method according to claim 1, further comprising
communicating the first and second brake pressures measured at the
respective first and second transducers to a control system.
3. The method according to claim 1, wherein determining, using the
one or more processors, whether the second transducer is
functioning within the designated operational parameters is
determined based on at least one of (a) a proportional difference
between the first brake pressure measured at the first transducer
and the second brake pressure measured at the second transducer or
(b) a direct difference between the first brake pressure measured
at the first transducer and the second brake pressure measured at
the second transducer.
4. The method according to claim 1, further comprising reporting a
failure when the second brake pressure measured at the second
transducer is outside of a designated range that is based on the
first brake pressure measured at the first transducer.
5. The method according to claim 1, further comprising obtaining
the first brake pressure reading at the first transducer and the
second brake pressure reading at the second transducer when a
distributed braking command is first applied on the lead powered
unit and is subsequently communicated to the remote powered
unit.
6. The method according to claim 1, wherein the lead powered unit
and the remote powered unit comprise first and second vehicles
respectively, the first and second vehicles being linked-together
and being one or more of an off-highway vehicle, an agricultural
vehicle, a mass transit transportation vehicle, a mass cargo
transportation vehicle, a marine vessel, or a rail vehicle.
7. The method according to claim 1, wherein the lead and remote
powered units are at least one of a part of a consist within a
series of linked powered units or are in separate consists within
the series of linked powered units.
8. The method according to claim 1, further comprising controlling
the DP system in a manner that disregards the second brake
pressure.
9. The method according to claim 1, further comprising reporting to
a control system that the second brake pressure is a false
reading.
10. The method according to claim 1, wherein the DP system is a
rail DP system comprising a series of linked rail vehicles, the
lead and remote powered units being first and second rail vehicles,
respectively, that are directly or indirectly linked together in
the rail DP system.
11. The method according to claim 1, wherein the lead powered unit
and the remote powered unit are locomotives.
12. The method according to claim 1, wherein the lead powered unit
and the remote powered unit are communicatively coupled through at
least one of a radio or physical cable.
13. The method according to claim 10, wherein the second brake
pressure is not used to control braking or traction operations of
the rail DP system when the second transducer is determined not to
be functioning within the designated operational parameters.
14. The method according to claim 10, wherein the first and second
rail vehicles are locomotives.
15. A method comprising: comparing a first brake pressure measured
at a first transducer that is part of a braking system on a lead
powered unit of a distributed power (DP) system to a second brake
pressure measured at a second transducer that is art of a braking
system on a remote powered unit of the DP system; and determining,
using one or more processors, whether the second transducer is
functioning within designated operational parameters when the DP
system is operating in a DP mode based on comparing the first brake
pressure to the second brake pressure; controlling the DP system in
a manner that disregards the second transducer when the second
transducer is determined not to be functioning within the
designated operational parameters; wherein each of the lead and
remote powered units is a separate and distinct powered unit
capable of providing tractive efforts to the DP system, the lead
and remote powered units being directly or indirectly coupled to
each other.
16. The method according to claim 15, wherein determining, using
the one or more processors, whether the second transducer is
functioning within the designated operational parameters includes
determining that the second brake pressure is invalid.
17. The method according to claim 15, wherein determining, using
the one or more processors, whether the second transducer is
functioning within the designated operational parameters is
determined based on at least one of (a) a proportional difference
between the first brake pressure measured at the first transducer
and the second brake pressure measured at the second transducer or
(b) a direct difference between the first brake pressure measured
at the first transducer and the second brake pressure measured at
the second transducer.
18. The method according to claim 15, further comprising reporting
a failure when the second brake pressure measured at the second
transducer is outside of a designated range that is based on the
first brake pressure measured at the first transducer.
Description
BACKGROUND
The inventive subject matter described herein relates generally to
communication systems and, more particularly, to determining
whether a reading from a pressure transducer is valid.
Powered systems such as, but not limited to, an off-highway
vehicle, marine powered propulsion plant or marine vessel, rail
vehicle systems or trains, stationary power plants, agricultural
vehicles, and transport vehicles, usually are powered by a power
unit, such as but not limited to a engine, such as but not limited
to a diesel engine. With respect to rail vehicle systems, the
powered system is a locomotive, which may be part of a train that
further includes a plurality of rail cars, such as freight cars.
Usually more than one locomotive is provided as part of the train,
where a grouping of locomotives is referred to as a locomotive
"consist." Locomotives are complex systems with numerous
subsystems, with each subsystem being interdependent on other
subsystems.
With respect to a train, under operator control, a railroad
locomotive supplies motive power (traction) to move the locomotive
and a load (e.g., non-powered railcars and their contents), and
applies brakes on the locomotive and/or on the non-powered railcars
to slow or stop the train. With respect to the locomotive, the
motive power is supplied by electric traction motors responsive to
an AC or DC power signal generated by the locomotive engine.
A railroad train has three separate brake systems. An air brake
system includes a fluid-carrying (typically the fluid includes air)
brake pipe that extends a length of the train and a railcar brake
system. Wheel brakes are applied or released at each locomotive and
at each railcar in response to a fluid pressure in the brake pipe.
An operator-controlled brake handle controls the brake pipe
pressure, venting the brake pipe to reduce the pressure to signal
the locomotives and railcars to apply the brakes, or charging the
brake pipe to increase the pressure to signal the locomotive and
railcars to release the brakes. For safe train operation, when
pressure in the brake pipe falls below a threshold value the brakes
default to an applied condition.
Each locomotive also has an independent pneumatic brake system
controlled by the operator to apply or release the locomotive
brakes. The independent pneumatic brake system, which is coupled to
the air brake system, applies the locomotive brakes by increasing
the pressure in the locomotive brake cylinders and releasing the
locomotive brakes responsive to a decrease in the cylinder air
pressure.
Finally, each locomotive is equipped with a dynamic brake system.
Activation of the dynamic brakes reconfigures the locomotive's
traction motors to operate as generators, with the inertia of the
locomotive wheels supplying rotational energy to turn the generator
rotor winding. Magnetic forces, developed by generator action,
resist wheel rotation and thus create wheel-braking forces. The
enemy produced by the generator is dissipated as heat in a resistor
grid in the locomotive and removed by one or more cooling blowers.
Use of the dynamic brakes is indicated to slow the train when
application of the locomotive independent brakes and/or the railcar
air brakes may cause the locomotive or railcar wheels to overheat
or when prolonged use may cause excessive wheel wear. For example,
the dynamic brakes may be applied when the train is traversing a
prolonged downgrade.
A train configured for distributed power (DP) operation has a lead
locomotive at a head-end of the train, and one or more remote
locomotives between the head-end and an end of the train. A DP
train may also include one or more locomotives at the end of the
train. The DP system further includes a distributed power train
control and communications system with a communications channel
(e.g., a radio frequency (RE) or a wire-based communications
channel) linking the lead and remote locomotives. Though DP
operation is disclosed specific to trains, similar systems are also
applicable for other powered systems disclosed herein.
The DP system generates traction and brake commands responsive to
operator-initiated (e.g., the operator in the lead locomotive)
control of a lead locomotive traction controller (or throttle
handle) or a lead locomotive brake controller (responsive to
operation of an air brake handle, a dynamic brake handle or an
independent brake handle). These traction or brake commands are
transmitted to the remote locomotives over the DP communications
channel. The receiving remote locomotives respond to the traction
or brake (apply and release) commands to apply tractive effort or
to apply/release the brakes and farther advise the lead locomotive
that the command was received and executed. For example, when the
lead locomotive operator operates the lead-locomotive throttle
controller to apply tractive effort at the lead locomotive,
according to a selected throttle notch number, the DP system issues
commands to each remote locomotive to apply the same tractive
effort (e.g., the same notch number). Each remote locomotive
replies to acknowledge execution of the command.
In certain DP systems, a plurality of pressure transducers are used
in an equalizing/control reservoir, brake pipe, brake cylinder,
etc. at the lead locomotive and at each remote locomotives to sense
when the lead locomotive makes a brake application and allows each
remote locomotive to make a similar brake application. This allows
for uniform braking to take place, which in turn keeps in-train
forces at acceptable limits.
FIG. 1 schematically illustrates an example distributed power train
10, traveling in a direction indicated by an arrowhead 11. A remote
locomotive 12A (also referred to as a remote unit) is controlled by
messages transmitted from either a lead locomotive 14 (also
referred to as a lead locomotive) or from a control tower 16.
Control tower commands are issued by a tower operator or dispatcher
either directly to the remote locomotive 12A or to the remote
locomotive 12A via the lead locomotive 14.
A trailing locomotive 13 coupled to the lead locomotive 14, forming
a consist, is controlled by the lead locomotive 14 via control
signals carried on an MU (multiple locomotive) line 17 connecting
the two units. Also, a trailing remote locomotive 12B coupled to
the remote locomotive 12A, forming another consist, is controlled
by the remote locomotive 12A via control signals carried on the MU
line 17.
Each of the locomotives 14 and 12A and the control tower 16
includes a DP transceiver 28L, 28R, 28T (also referred to as a DP
radio) and a DP antenna 29 for receiving and transmitting the DP
communication messages. The DP transceivers are referred to by
suffixed reference numerals 28L, 28R and 28T indicating location in
the lead locomotive, remote locomotive, and the control tower,
respectively.
The DP commands are typically generated in a lead station 30L in
the lead unit 14 responsive to operator control of the motive power
and braking controls in the lead locomotive 14, as described above.
The remote locomotive 12A also includes a remote station 32R for
processing messages from the lead locomotive 14 and for issuing
reply messages and commands.
The distributed power train 10 further comprises a plurality of
railcars 20 interposed between the locomotives illustrated in FIG.
1 and connected to a brake pipe 22. The railcars 20 are provided
with an air brake system (certain components of which are not shown
in FIG. 1) that applies the railcar air brakes in response to a
pressure drop in the brake pipe 22 and releases the air brakes in
response to a pressure increase in the brake pipe 22. The brake
pipe 22 runs the length of the train for conveying the air pressure
changes specified by air brake controllers 24 in the locomotives 14
and 12A. A plurality of transducers 69 is provided. The plurality
of transducers 69 are associated with the equalizing/control
reservoir, brake pipe, and brake cylinder at each brake controller
24 at each lead and remote locomotive. The transducers 69
communicate with the lead station 30L in the lead locomotive 14 to
identify the brake application that the driver is commanding at the
lead locomotive. The lead station then transmits this brake
application data to the remote station 32R via the DP radios 28L
and 28R. The remote station 32R then commands the remote brake
controllers 24 to apply brakes as commanded from the lead
locomotive. The transducers 69 communicate with the remote station
32R in the remote locomotive 12A to identify that the remote
locomotive 12A is making its braking application in response to the
braking application made by the lead locomotive 14.
In distributed power applications, it is especially critical to
have valid and accurate pressure transducer data. During times of
communication interruption, if a brake application is applied at
the lead locomotive, the remote locomotive cannot receive this
brake command and the lead locomotive may apply brakes at the front
part of the train very rapidly while the rear part of the train the
brakes are being applied at a much slower rate. Such an application
of brakes may result in experiencing high in-train forces, which
are unacceptable during train motoring. Additionally, pressure
transducers may fail at an acceptable pressure and provide a false
reading to the lead locomotive, or, more specifically, a train
control system. This false reading will indicate to the system that
it is safe to operate in a nominal state. The false reading might
allow the system to make an unacceptable action.
Therefore, owners and operators of locomotives and trains would
benefit from being able to detect when a failed or stuck pressure
transducer is realized where the detection ensures that the data
associated with the detection is current data. Owners and operators
would also benefit from having fewer working parts in the
distributed power system; therefore, an additional benefit would be
realized if the detection is accurate enough to reduce the number
of redundant transducers currently required.
BRIEF DESCRIPTION
Embodiments of the presently described inventive subject matter
relate to a method, system, and computer software code for
verifying validity of a pressure reading from a transducer on a
remote powered system. The system comprises a comparator subsystem
configured to evaluate a pressure reading differential taken
between a first transducer that is part of a braking system on a
lead powered system and a second transducer that is a part of a
braking system on a remote powered system, wherein the pressure
reading differential is taken when the lead powered system and the
remote powered system are operating in a distributed power
application. (Distributed power "application" or "mode" means
coordinated control of braking, power/traction, and/or other
operations as between two or more linked powered systems, e.g., the
lead and remote powered systems.)
The method comprises comparing pressure measured at a first
transducer to pressure measured at a second transducer to determine
whether the second transducer functions properly when the powered
system is operating in a distributed power mode.
The computer software code is stored on a computer readable media
and is executable with a processor. The computer software code
comprises a computer software module for comparing pressure
measured at a first transducer to pressure measured at a second
transducer to determine whether the second transducer functions
properly when the powered system is operating in a distributed
power mode.
A method for verifying operation of a pressure transducer comprises
obtaining a first pressure reading from a first transducer in a
first rail vehicle, wherein the first pressure reading relates to a
braking pressure in the first rail vehicle. The method further
comprises obtaining a second pressure reading from a second
transducer in a second rail vehicle, wherein the second pressure
reading relates to a braking pressure in the second rail vehicle,
and wherein the first and second pressure readings are taken when
the first and second rail vehicles are operating in a distributed
power application, said first and second rail vehicles being
indirectly or directly linked together as part of a series of
linked rail vehicles. The method also comprises carrying out a
comparison of the first pressure reading to the second pressure
reading, and determining whether the second transducer is
functioning within designated operational parameters based on the
comparison.
BRIEF DESCRIPTION OF THE DRAWINGS
A more particular description of the inventive subject matter
briefly described above will be rendered by reference to specific
embodiments thereof that are illustrated in the appended drawings.
Understanding that these drawings depict only typical embodiments
of the inventive subject matter and are not therefore to be
considered to be limiting of its scope, the embodiments of the
inventive subject matter will be described and explained with
additional specificity and detail through the use of the
accompanying drawings in which:
FIG. 1 illustrates a prior art representation of a distributed
power train;
FIG. 2 depicts a flowchart illustrating an example method for
verifying validity of a pressure reading from a transducer on a
remote powered system in a distributed power powered system;
FIG. 3 depicts another flowchart illustrating an example method for
verifying validity of a pressure reading from a transducer on a
remote powered system in a distributed power powered system;
FIG. 4 illustrates, in block diagram form, elements for reporting
and acting on a fault message; and
FIG. 5 depicts a flowchart illustrating an example method for
verifying operation of a pressure transducer.
DETAILED DESCRIPTION
Reference will be made below in detail to example embodiments of
the inventive subject matter, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
numerals used throughout the drawings refer to the same or like
parts. As disclosed below, multiple versions of a same element may
be disclosed. Likewise, with respect to other elements, a singular
version is disclosed. Neither multiple versions disclosed nor a
singular version disclosed shall be considered limiting.
Specifically, although multiple versions are disclosed, a singular
version may be utilized. Likewise, where a singular version is
disclosed, multiple versions may be utilized.
Though example embodiments of the presently described inventive
subject matter are described with respect to rail vehicles, or
railway transportation systems, specifically trains and
locomotives, example embodiments of the inventive subject matter
are also applicable for use with other powered systems, such as but
not limited to marine vessels, stationary units such as power
plants, off-highway vehicles, agricultural vehicles, and/or
transportation vehicles, each which may use at least one engine.
Towards this end, when discussing a specified mission, this
includes a task or requirement to be performed by the powered
system. Therefore, with respect to a railway vehicle, marine
vessel, agricultural vehicle, transportation vehicle, or
off-highway vehicle applications, this may refer to the movement of
a collective powered system (where more than one individual powered
system is provided) from a present location to a destination. In
the case of stationary applications, such as but not limited to a
stationary power generating station or network of power generating
stations, a specified mission may refer to an amount of wattage
(e.g., MW/hr) or other parameter or requirement to be satisfied by
the powered system.
Though diesel powered systems are readily recognized when
discussing trains or locomotives, one or more embodiments of the
inventive subject matter may also be utilized with non-diesel
powered systems, such as but not limited to natural gas powered
systems, bio-diesel powered systems, etc. Furthermore, the
individual powered system may include multiple engines, other power
sources, and/or additional power sources, such as, but not limited
to, battery sources, voltage sources (such as but not limited to
capacitors), chemical sources, pressure based sources (such as but
not limited to spring and/or hydraulic expansion), electrical
current sources (such as but not limited to inductors), inertial
sources (such as but not limited to flywheel devices),
gravitational-based power sources, and/or thermal-based power
sources. Additionally, the power source may be external, such as,
but not limited to, an electrically powered system, such as a
locomotive or train, where power is sourced externally from
overhead catenary wire, a third rail, and/or magnetic levitation
coils.
Example embodiments of the inventive subject matter solve problems
in the art by providing a method, system, and computer implemented
method, such as a computer software code or computer readable
media, for verifying validity of a pressure reading from a
transducer on a remote powered system. With respect to locomotives,
example embodiments of the presently described inventive subject
matter are operable when the locomotive consist is in distributed
power operations. Distributed power operations, however, are not
only applicable to locomotives or trains. The other powered systems
disclosed herein may also operate in a distributed power
configuration.
In this document the term "locomotive consist" is used. As used
herein, a locomotive consist may be described as having one or more
locomotives in succession, connected together so as to provide
motoring and/or braking capability. The locomotives are connected
together where no train cars are in between the locomotives. The
train can have more than one locomotive consists in its
composition. Specifically, there can be a lead consist and one or
more remote consists, such as midway in the line of cars and
another remote consist at the end of the train. Each locomotive
consist may have a first locomotive and trail locomotive(s). Though
a first locomotive is usually viewed as the lead locomotive, the
first locomotive in a multi-locomotive consist may be physically
located in a physically trailing position.
Though a locomotive consist is usually viewed as involving
successive locomotives, a consist group of locomotives may also be
recognized as a consist even when one or more rail cars separate
the locomotives, such as when the locomotive consist is configured
for distributed power operation, wherein throttle and braking
commands are relayed from the lead locomotive to the remote trains
by a radio link or physical cable. Towards this end, the term
locomotive consist should not be considered a limiting factor when
discussing multiple locomotives within the same train.
As disclosed herein, the idea of a consist may also be applicable
when referring to other types of powered systems including, but not
limited to, marine vessels, off-highway vehicles, agricultural
vehicles, and/or stationary power plants, that operate together so
as to provide motoring, power generation, and/or braking
capability. Therefore, even though the term locomotive consist is
used herein in regards to certain illustrative embodiments, this
term may also apply to other powered systems. Similarly,
sub-consists may exist. For example, the powered system may have
more than one power generating unit. For example, a power plant may
have more than one diesel electric power unit where optimization
may be at the sub-consist level. Likewise, a locomotive may have
more than one diesel power unit. Furthermore though the examples
are disclosed with respect to a rail vehicle, such disclosures are
not to be considered limiting. The example embodiments are also
applicable to the other powered systems disclosed herein.
An apparatus, such as a data processing system, including a CPU,
memory, I/O, program storage, a connecting bus, and other
appropriate components, could be programmed or otherwise designed
to facilitate the practice of the method of the inventive subject
matter. Such a system would include appropriate program means for
executing the method of the inventive subject matter.
Also, an article of manufacture, such as a pre-recorded disk,
computer readable media, or other similar computer program product,
for use with a data processing system, could include a storage
medium and program means recorded thereon for directing the data
processing system to facilitate the practice of the method of the
inventive subject matter. Such apparatus and articles of
manufacture also fall within the spirit and scope of the inventive
subject matter.
Broadly speaking, a technical effect is to verify validity of a
pressure reading from a transducer on a remote powered system. To
facilitate an understanding of the example embodiments of the
inventive subject matter, it is described hereinafter with
reference to specific implementations thereof. Example embodiments
of the inventive subject matter may be described in the general
context of computer-executable instructions, such as program
modules, being executed by any device, such as but not limited to a
computer, designed to accept data, perform prescribed mathematical
and/or logical operations usually at high speed, where results of
such operations may or may not be displayed. Generally, program
modules include routines, programs, objects, components, data
structures, etc. that perform particular tasks or implement
particular abstract data types. For example, the software programs
that underlie example embodiments of the inventive subject matter
can be coded in different programming languages, for use with
different devices, or platforms. In the description that follows,
examples of the inventive subject matter may be described in the
context of a web portal that employs a web browser. It will be
appreciated, however, that the principles that underlie example
embodiments of the inventive subject matter can be implemented with
other types of computer software technologies as well.
Moreover, example embodiments of the inventive subject matter may
be practiced with other computer system configurations, including
multiprocessor systems, microprocessor-based or programmable
consumer electronics, minicomputers, mainframe computers, and the
like. Example embodiments of the inventive subject matter may also
be practiced in distributed computing environments where tasks are
performed by remote processing devices that are linked through at
least one communications network. In a distributed computing
environment, program modules may be located in both local and
remote computer storage media including memory storage devices.
Referring now to the drawings, embodiments of the presently
described inventive subject matter will be described. Example
embodiments of the inventive subject matter can be implemented in
numerous ways, including as a system (including a computer
processing system), a method (including a computerized method), an
apparatus, a computer readable medium, a computer program product,
a graphical user interface, including a web portal, or a data
structure tangibly fixed in a computer readable memory. Several
embodiments of the inventive subject matter are discussed
below.
FIG. 2 depicts a flowchart illustrating a method for verifying
validity of a pressure reading from a transducer on a remote
powered system in a distributed power powered system, the
distributed power powered system including the remote powered
system and a lead powered system. The method in the flowchart 40
comprises measuring pressure at a first transducer on the lead
powered system when a distributed braking command is applied on the
lead powered system, at 42. The method continues, at 44, with
applying the distributed braking command on the remote powered
system. Pressure is measured at a second transducer on the remote
powered system, at 46. The pressure measured at the first
transducer is compared to the pressure measured at the second
transducer to determine whether the second transducer functions
properly, at 48. Comparing the pressure measured, at 48, may
further comprise comparing the pressure measured based on a
proportional difference and/or a direct difference over a nominal
period of time. The compared measured pressures are communicated to
a control system of the powered system, at 50. When the pressure
measured from the second transducer is outside of a designated
acceptable range when compared to the pressure measured from the
first transducer, a failure is reported, at 52. In one embodiment,
the proportional difference is an integral of a pressure difference
over a time period, used to create a threshold, whereas the direct
difference is an absolute difference between any two discrete
periods of time which are used to create the same, or nearly
equivalent, threshold. The proportional difference and/or the
direct difference may be used in a calculation for analyzing, or
determining, air flow. Further information about analysis of air
flow may be found in U.S. Pat. Nos. 6,375,276 or 4,553,723, both
herein incorporated by reference.
FIG. 3 depicts a flowchart illustrating a method for verifying
validity of a pressure reading from a transducer on a remote
powered system in a distributed power powered system. The method in
the flowchart 60 comprises comparing pressure measured at a first
transducer that is part of a braking system on a lead powered
system to pressure measured at a second transducer that is part of
a braking system on a remote powered system to determine whether
the second transducer functions properly when the distributed power
powered system is operating in a distributed power mode, at 62.
Comparing the pressure measured, at 62, further comprises comparing
the pressure measured based on a proportional difference and/or a
direct difference over a nominal period of time. The method further
comprises communicating the compared measured pressures to a
control system of the distributed power powered system, at 64. When
the pressure measured from the second transducer is outside of an
acceptable range when compared to the pressure measured from the
first transducer, a failure is reported, at 66. The method further
includes obtaining a pressure reading at the first transducer, that
is part of the braking system on the lead powered system, and at
the second transducer, that is part of the braking system on the
remote powered system, when a distributed braking command is
applied first on the lead powered system and is then relayed to the
remote powered system, at 68.
The methods shown in flowcharts 40, 60 may be performed with a
computer software code having computer software modules where the
computer software code is stored on computer media and is executed
with a processor. Thus each process flow in the flowcharts 40, 60
may be performed by a computer software module specific to the
process contained, in a specific process. For example, comparing
pressure measured at a first transducer to pressure measured at a
second transducer to determine whether the second transducer
functions properly when the powered system is operating in a
distributed, power mode, at 62, may be performed with a computer
software module for comparing pressure measured at a first
transducer to pressure measured at a second transducer to determine
whether the second transducer functions properly when the powered
system is operating in a distributed power mode.
A processor 71 disclosed to implement the methods and as disclosed
in FIG. 4 below may not be a generic computer. Specifically, the
processor 71 is unique to operate within an environment that it is
exposed to when part of the powered system. Therefore a processor
aboard the locomotive is not only specific to perform the methods
disclosed above, but it is also able to withstand the environmental
conditions experienced aboard the locomotive.
FIG. 4 depicts an example embodiment of a system for verifying
validity of a pressure reading from a transducer on a remote
powered system. For illustration purposes, FIG. 4 uses a train
having a lead and remote locomotive. However, as disclosed above,
this embodiment is application to a plurality of other powered
systems operating together. The system comprises a comparator
subsystem 70 located in the remote locomotive 12A, configured to
evaluate a pressure reading differential taken between a first
transducer 72 that is part of a braking system on a lead locomotive
14 and a second transducer 74 that is a part of a braking system on
a remote locomotive 12A. The pressure reading differential is taken
when the lead locomotive 14 and the remote locomotive 12A are
operating in a distributed power application. The first transducer
72 pressure value is transmitted over a radio communication link
established between the DP radio 28L at the lead and 28R at the
remote. An operator 5 is also illustrated as being aboard the lead
locomotive 14.
The comparator subsystem 70 comprises the processor 71 to compare a
pressure reading from the first transducer 72 to a pressure reading
from the second transducer 74. The pressure reading differential
may be based on a proportional difference and/or a direct
difference over a nominal period of time. The system further
comprising a communication network 76 for reporting pressure data
from the first transducer 72 to the brake system on the lead loco
14 and the second transducer 74 to the brake system on the remote
loco 12A. More specifically, the pressure data from the second
transducer 74 reports pressure data to the comparator subsystem 70
via the communication network 76. The comparator subsystem 70 and
processor 71 may be integrated with the remote station 30R. The
first transducer reports pressure data through the communication
network 76 to the lead brake system 30L where it is then
transmitted over the radio communication link to the remote
locomotive 12A where it is reported to the comparator subsystem 70.
The comparator subsystem 70 is also in communication with a control
system 78 of the remote locomotive wherein pressure reading
differential information is communicated to the control system 78.
The control system 78 may also be integral with the remote station
30R.
In an example embodiment, a control-area network ("CAN") bus may be
utilized for communicating between the various elements in FIG. 4
that are on a specific locomotive. The DP radios 28L, 28R are
provided to communicate between the locomotives. Using the CAN bus
should result in actuate signals being transmitted and received at
a high degree of integrity. Because of this integrity, a single
transducer 74 may be used on the remote locomotive 12A.
In another example embodiment, where a train has a lead consist and
a trail consist, instead of having a transducer only on the lead
locomotive in each consist, a transducer is included on each
locomotive in each consist. Within each consist, the pressure data
can be compared across each consist locomotive. In another
embodiment the pressure data across each consist can then be
compared to the other consist. For example, after data from each
locomotive in a trial consist is compared, the collective consist
data may be compared to the consist pressure data from the lead
consist. The lead locomotive and remote locomotive can be part of
the same consist and/or may be part of separate consists.
Another embodiment relates to a method for verifying operation of a
pressure transducer, as illustrated in FIG. 5. A flowchart 80
illustrates the method comprises obtaining a first pressure reading
from a first transducer in a first rail vehicle, at 82. The first
pressure reading relates to a braking pressure in the first rail
vehicle. The method further comprises obtaining a second pressure
reading from a second transducer in a second rail vehicle, at 84.
The second pressure reading relates to a braking pressure in the
second rail vehicle. The first and second pressure readings are
taken when the first and second rail vehicles are operating in a
distributed power application. The first and second rail vehicles
are indirectly or directly linked together as part of a series of
linked rail vehicles. The method further comprises carrying out a
comparison of the first pressure reading to the second pressure
reading, at 86, and determining whether the second transducer is
functioning within designated operational parameters based on the
comparison, at 88. ("Operational parameter" refers to an aspect or
characteristic of the transducer in operation. "Designated"
operational parameter refers to a particular value (or range of
values) for each operational parameter that reflects a particular
operational condition, such as nominal or proper operation.)
While the inventive subject matter has been described with
reference to various example embodiments, it will be understood by
one of ordinary skill in the art that various changes, omissions
and/or additions may be made and equivalents may be substituted for
elements thereof without departing from the spirit and scope of the
inventive subject matter. In addition, many modifications may be
made to adapt a particular situation or material to the teachings
of the inventive subject matter without departing from the scope
thereof. Therefore, it is intended that the inventive subject
matter not be limited to the particular embodiment disclosed as the
best mode contemplated for carrying out this inventive subject
matter, but that the inventive subject matter will include all
embodiments falling within the scope of the appended claims.
Moreover, unless specifically stated any use of the terms first,
second, etc. do not denote any order or importance, but rather the
terms first, second, etc. are used to distinguish one element from
another.
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